Glycerol residue recycling process and glycerol residue recycling treatment system

Abstract

The invention discloses a glycerol residue recycling process and a glycerol residue recycling treatment system, glycerol residue is diluted and then filtered to remove impurities, calcium oxide and sodium metaaluminate are added for reaction to generate Friedel's salt for recycling, the pH of filtrate is adjusted, sodium carbonate is added to generate calcium carbonate for recycling, and the glycerol residue is recycled. The method comprises the following steps: carrying out fine separation on glycerol and chlorine salt in glycerol residues, then carrying out microfiltration to remove glue, carrying out ultrafiltration separation on high-polymerization-degree polyglycerol for recycling, and carrying out nanofiltration separation on low-polymerization-degree polyglycerol for recycling, so as to finally obtain a glycerol solution for recycling. Inorganic salt is prepared into a heavy metal capturing agent, the heavy metal capturing agent, refined calcium carbonate and glycerol are prepared into a water treatment carbon source, low-polymerization-degree polyglycerol is prepared into refined polyglycerol, high-polymerization-degree polyglycerol is prepared into a liquid cement grinding aid, fine recycling of resources is achieved, flammable and explosive solvents are not used in the treatment process, and safety is high.

Description

Technical Field

[0001] The invention relates to the technical field of resource recycling, and in particular to a glycerin residue recycling process and a glycerin residue recycling treatment system. Background Art

[0002] The most widely used technology for refining crude glycerin into refined glycerin is distillation separation. No matter which distillation technology is used, glycerin residue will be produced after distillation. The main components of glycerin residue are inorganic salts, glycerin (glycerin, polymerized glycerin) and impurities. Glycerin residue is difficult to handle. Treatment by landfill, incineration and other methods not only pollutes the environment but also wastes resources. A feasible reuse process is needed to recover the available resources and realize the resource utilization of waste.

[0003] In order to avoid the generation of sulfide gas during the distillation of glycerol conditioned by sulfuric acid, over-distillation will not be carried out. The resulting distillation mother liquor contains a high amount of water. The solid residue obtained by centrifugation of the distillation mother liquor is the glycerol residue, which contains more than 70% of inorganic salts. Its resource utilization is mainly to recover waste salt. In Chinese patent CN 114773159 B, the glycerol residue mainly composed of sulfate is recycled by crystallization. The glycerol residue is diluted with water and then crystallized at low temperature for salt separation. The solid phase of the crystallized salt separation is sodium sulfate. This process is only for glycerol residue in the sulfate system, and does not achieve fine utilization of glycerol.

[0004] In order to improve the recovery rate of glycerol during the distillation of glycerol conditioned by hydrochloric acid, it is often "baked" at high temperature. The inorganic salts crystallize out as the water content decreases, and are washed and reused after separation. The liquid phase of the distillation mother liquor has a low water content. After cooling, the mother liquor condenses into solid and semi-solid residues. The glycerol residue contains less than 50% inorganic salts and more than 35% glycerol (glycerol, polymerized glycerol). Its resource utilization is mainly to recover glycerol. For the reuse of glycerol residues in the chloride system, an organic solvent extraction process for recovering glycerol can be used. This process commonly uses organic solvents such as ethanol and isopropanol, which are flammable and explosive, and have poor safety. Molecular distillation and other evaporation processes for recovering glycerol can be used. This process can only evaporate and separate the glycerol in the glycerol, and the polymerized glycerol and chloride salts are co-crystallized and discarded, without realizing the fine utilization of resources. Conventional inorganic chloride salts have relatively high solubility in water, making it difficult to use crystallization processes to separate and recycle chloride ions. Ionic resins can be used to absorb salts to recover glycerol, but this process cannot recover inorganic salts, without realizing the fine utilization of resources.

[0005] At present, the following problems are common in the existing glycerin residue recycling process:

[0006] 1) Organic solvents have poor safety;

[0007] 2) Inorganic salts, glycerol, and polyglycerol are not completely separated, and fine utilization of resources is not achieved;

[0008] 3) Chloride ions are difficult to separate, and there is a lack of targeted methods for glycerol residues in chloride salt systems. Summary of the invention

[0009] In order to overcome the above-mentioned defects, the present invention provides a glycerin residue recycling process and a glycerin residue recycling treatment system, which realizes the fine recycling and utilization of glycerin residue resources, and the whole process is highly safe.

[0010] The technical solution adopted by the present invention to solve the technical problem is: a glycerin residue recycling process, comprising the following steps:

[0011] Step 1: Glycerine residue dilution:

[0012] Dilute the glycerin residue whose inorganic salt components are mainly chloride salts with water;

[0013] Step 2: Filter and remove impurities:

[0014] Filtering the glycerin residue dilution to remove colloidal impurities in the glycerin residue dilution;

[0015] Step 3: Freund's salt method for dechlorination:

[0016] The filtered glycerine residue dilution liquid is pumped into a reactor, and calcium oxide and sodium aluminate are added to the reactor to react to generate Fred salt, and the Fred salt precipitate produced by the reaction is separated from the supernatant, the Fred salt precipitate is recycled, and the supernatant flows out, wherein the addition amount of calcium oxide and sodium aluminate is according to n(Ca):n(Al):n(Cl)=5-20:2-5:1;

[0017] Step 4: Filtrate conditioning:

[0018] Testing the chloride ion content of the supernatant after separating the Fred salt precipitate in step 3;

[0019] If the chloride ion content is >500 mg / L, repeat step 3;

[0020] If the chloride ion content is ≤500 mg / L, sulfuric acid is added to adjust the pH of the supernatant to neutral, and sodium carbonate is added to react with calcium ions in the supernatant after separation of Fred salt precipitation to form calcium carbonate. The amount of sodium carbonate added is based on the standard that no precipitation is generated by continuing to add sodium carbonate to the supernatant after separation of Fred salt precipitation, and the calcium carbonate precipitate is separated and recycled;

[0021] Step 5: Microfiltration to remove glue:

[0022] The supernatant produced in step 4 is filtered using a microfiltration membrane to separate the macromolecular organic matter with a molecular weight greater than 1 million and the residual colloid into a microfiltration concentrate to obtain a microfiltration clear liquid;

[0023] Step 6: Ultrafiltration separation:

[0024] The microfiltration clear solution is filtered through an ultrafiltration membrane, and the high-polymerization degree polyglycerol with a molecular weight of more than 1000 is separated into an ultrafiltration concentrate for recovery as a raw material for liquid cement grinding aid, and ultrafiltration clear solution is obtained at the same time;

[0025] Step 7: Nanofiltration separation:

[0026] The ultrafiltration clear is filtered through a nanofiltration membrane, and low-polymerization degree polyglycerol with a molecular weight of 200 to 1000 is separated together with sulfate into nanofiltration concentrated water for recycling, and a nanofiltration clear liquid with glycerol as the main component is obtained, and the nanofiltration clear liquid is used as a glycerol solution.

[0027] As a further improvement of the present invention, when diluting the glycerol residue whose inorganic salt component is mainly chloride salt with water in step 1, the specific gravity is controlled between 1 and 1.05 and the salinity is controlled between 5000 and 50000 mg / L.

[0028] As a further improvement of the present invention, in the step 2, a filter press is used to filter the glycerol dilution in the step 1 to remove colloidal impurities.

[0029] As a further improvement of the present invention, after the glycerin residue dilution liquid is added into the reactor in step three, the agitator of the reactor is started, the agitator speed is 80 to 500 r / min, and the temperature of the glycerin residue dilution liquid in the reactor is controlled at 10 to 30° C., and then calcium oxide and sodium aluminate are added to react.

[0030] As a further improvement of the present invention, the Fred salt precipitate obtained in step three is separated by filter pressing and then recycled as a raw material for heavy metal capture agent.

[0031] As a further improvement of the present invention, the calcium carbonate precipitate separated in step 4 is purified by washing to obtain refined calcium carbonate for industrial production.

[0032] As a further improvement of the present invention, the inorganic salt in the nanofiltration concentrated water obtained in step seven is adsorbed by an ion resin to obtain refined polyglycerol for industrial production.

[0033] A glycerin residue recycling treatment system comprises a glycerin residue dilution tank, a primary filter press, a secondary filter press, a tertiary filter press, a reactor, a filtrate conditioning tank, a chloride ion concentration detector, a microfiltration membrane device, a microfiltration water production barrel, an ultrafiltration membrane device, an ultrafiltration water production barrel and a nanofiltration membrane device. The glycerin residue dilution tank is connected with the inlet of the primary filter press through a pipeline. The glycerin residue dilution liquid in the glycerin residue dilution tank can be sent into the filter press through a lifting pump. The filter press can filter the glycerin dilution liquid to remove colloidal impurities. The water filter port of the filter press is connected with the liquid inlet of the reactor through a pipeline, and the filtrate is then transported into the reactor. The reactor is also provided with The reagent adding port, the supernatant discharge port and the precipitation discharge port can be opened and closed. The reagent adding port is used for adding reagents. The supernatant discharge port is used for discharging the supernatant formed by precipitation after the reaction in the reactor. The precipitation discharge port is used for discharging the precipitation at the bottom of the reactor. The precipitation discharge port of the reactor is connected with the inlet of the secondary filter press through a pipeline. The secondary filter press can filter and dehydrate the water-containing precipitation discharged from the reactor to obtain solid Fred salt. The supernatant discharge port of the reactor is connected with the water inlet of the filtrate conditioning tank through a pipeline. The chloride ion concentration detector can detect the chloride ion concentration of the liquid in the filtrate conditioning tank. The filtrate conditioning tank is also connected to the liquid inlet of the reactor through a pipeline. The liquid in the filtrate conditioning tank that is detected to have excessive chloride ion concentration can be sent back to the reactor through a lifting pump. The filtrate conditioning tank is provided with a dosing port, a conditioning clear liquid discharge port and a precipitation separation port. The dosing port is used to add chemicals. The precipitation separation port of the filtrate conditioning tank is connected to the inlet of a three-stage filter press through a pipeline. The three-stage filter press can filter and dehydrate the water-containing precipitate discharged from the filtrate conditioning tank to obtain solid calcium carbonate. The conditioning clear liquid discharge port of the filtrate conditioning tank is connected to the liquid inlet of the microfiltration membrane device through a pipeline. The microfiltration membrane in the microfiltration membrane device can filter the filtrate. The conditioned clear liquid discharged from the conditioning pool is subjected to microfiltration treatment, the microfiltration clear liquid of the microfiltration membrane device is discharged into the microfiltration water production barrel through a pipeline, the microfiltration water production barrel is connected with the liquid inlet of the ultrafiltration membrane device through a pipeline, the microfiltration clear liquid in the microfiltration water production barrel can be sent into the ultrafiltration membrane device through a lifting pump, the ultrafiltration membrane of the ultrafiltration membrane device can perform ultrafiltration treatment on the microfiltration clear liquid, the ultrafiltration clear liquid of the ultrafiltration membrane device is discharged into the ultrafiltration water production barrel through a pipeline, the ultrafiltration water production barrel is connected with the liquid inlet of the nanofiltration membrane device through a pipeline, the ultrafiltration clear liquid in the ultrafiltration water production barrel can be sent into the nanofiltration membrane device through a lifting pump, and the nanofiltration membrane of the nanofiltration membrane device can perform nanofiltration treatment on the ultrafiltration clear liquid.

[0034] As a further improvement of the present invention, there are also Fred salt deep processing equipment, calcium carbonate washing and purification equipment, high-polymerization degree polymerized glycerol deep processing equipment, low-polymerization degree polymerized glycerol deep processing equipment and glycerol solution deep processing equipment. The Fred salt deep processing equipment is provided with a feed inlet for adding solid Fred salt and an auxiliary agent addition inlet for adding auxiliary agents. The Fred salt deep processing equipment can prepare solid Fred salt produced by the secondary filter press through auxiliary agents to prepare solid heavy metal capture agents. The calcium carbonate washing and purification equipment can wash and remove impurities from solid calcium carbonate-containing substances produced by the tertiary filter press to obtain a high-purity solid refined calcium carbonate product. The ultrafiltration concentrate discharge port of the ultrafiltration membrane device is connected to the feed inlet of the high-polymerization degree polymerized glycerol deep processing equipment through a pipeline. The ultrafiltration concentrate The high-polymerization-degree polymerized glycerol deep processing equipment can be discharged into the high-polymerization-degree polymerized glycerol deep processing equipment, and the high-polymerization-degree polymerized glycerol deep processing equipment can prepare the high-polymerization-degree polymerized glycerol in the ultrafiltration concentrate through additives to prepare liquid cement grinding aids. The nanofiltration concentrate discharge port and the nanofiltration clear night discharge port of the nanofiltration membrane device are respectively connected with the liquid inlet of the low-polymerization-degree polymerized glycerol deep processing equipment and the glycerol solution deep processing equipment through pipelines. The nanofiltration concentrate and the nanofiltration clear night can be discharged into the low-polymerization-degree polymerized glycerol deep processing equipment and the glycerol solution deep processing equipment respectively. The low-polymerization-degree polymerized glycerol deep processing equipment is provided with an ion resin, and the ion resin can nanofilter the inorganic salts in the concentrate to finally obtain liquid refined polymerized glycerol. The glycerol solution deep processing equipment can prepare the nanofiltration clear night through additives to prepare a liquid water treatment carbon source.

[0035] As a further improvement of the present invention, the glycerin residue dilution tank, the reaction kettle and the filtrate conditioning tank are all provided with a stirrer for stirring the mixture.

[0036] The beneficial effects of the present invention are as follows: the present invention carries out targeted treatment on the glycerol residue of the chloride salt system, and no flammable and explosive solvent is used in the treatment process, so the safety is high; the present invention carries out fine separation of the chloride salt, glycerol, low-polymerization-degree polyglycerol and high-polymerization-degree polyglycerol in the glycerol residue, prepares the inorganic salt into a heavy metal scavenger and refined calcium carbonate, prepares the glycerol into a water treatment carbon source, prepares the low-polymerization-degree polyglycerol into refined polyglycerol, and prepares the high-polymerization-degree polyglycerol into a liquid cement grinding aid, so as to realize the fine recycling of resources. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 This is a process flow chart of glycerin residue recycling of the present invention;

[0038] Figure 2 This is a schematic diagram of the glycerin residue recycling system of the present invention. DETAILED DESCRIPTION

[0039] In order to make the advantages, technical solutions and innovations of the present invention clearer, the present invention will be further described in detail below in conjunction with the above drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative work are within the protection scope of the present invention.

[0040] Embodiment: A glycerol residue recycling process,

[0041] The steps include:

[0042] Step 1: Glycerine residue dilution:

[0043] Dilute the glycerin residue whose inorganic salt components are mainly chloride salts with water;

[0044] Step 2: Filter and remove impurities:

[0045] Filtering the glycerin residue dilution to remove colloidal impurities in the glycerin residue dilution;

[0046] Step 3: Freund's salt method for dechlorination:

[0047] The filtered glycerine residue dilution liquid is pumped into the reactor 5, and calcium oxide and sodium aluminate are added to the reactor 5 to react to generate Fred salt (Ca4Al2Cl2(OH)12), and the Fred salt precipitate produced by the reaction is separated from the supernatant, the Fred salt precipitate is recycled, and the supernatant flows out, wherein the addition amount of calcium oxide and sodium aluminate is added according to n(Ca)∶n(Al):n(Cl)=5~20∶2~5∶1;

[0048] Freund's salt reaction mechanism

[0049] (1)2NaAlO2+4H2O→2Al(OH)3+2NaOH;

[0050] (2)4Ca(OH)2+2Al(OH)3→Ca4Al2(OH)14;

[0051] (3)Ca4Al2(OH)14+2Cl - →Ca4Al2Cl2(OH)12+2OH - ;

[0052] (4)CaCl2+3Ca(OH)2+2NaAlO2+8H2O→

[0053] 2Ca2Al(OH)6Cl·4H2O+2NaOH;

[0054] Step 4: Filtrate conditioning:

[0055] Testing the chloride ion content of the supernatant after separating the Fred salt precipitate in step 3;

[0056] If the chloride ion content is >500 mg / L, repeat step 3;

[0057] If the chloride ion content is ≤500 mg / L, sulfuric acid is added to adjust the pH of the supernatant to neutral, and sodium carbonate is added to react with calcium ions in the supernatant after separation of Fred salt precipitation to form calcium carbonate. The amount of sodium carbonate added is based on the standard that no precipitation is generated by continuing to add sodium carbonate to the supernatant after separation of Fred salt precipitation, and the calcium carbonate precipitate is separated and recycled;

[0058] Step 5: Microfiltration to remove glue:

[0059] The supernatant produced in step 4 is filtered using a microfiltration membrane to separate the macromolecular organic matter with a molecular weight greater than 1 million and the residual colloid into a microfiltration concentrate to obtain a microfiltration clear liquid;

[0060] Step 6: Ultrafiltration separation:

[0061] The microfiltration clear is filtered through an ultrafiltration membrane, and the high-polymerization degree polyglycerol with a molecular weight of more than 1000 is separated into the ultrafiltration concentrate for recovery as a raw material for a liquid cement grinding aid, and at the same time, the ultrafiltration clear is obtained. The high-polymerization degree polyglycerol with a molecular weight of more than 1000, mainly polyglycerol with a molecular weight of more than 10, contains polar hydroxyl groups necessary for traditional cement grinding aids. These polar groups can combine with cement particles to prevent them from reaggregating during grinding. By adding certain additives for mutual matching, a liquid cement grinding aid can be obtained for cement production;

[0062] Step 7: Nanofiltration separation:

[0063] The ultrafiltration clear is filtered through a nanofiltration membrane, and low-polymerization degree polyglycerol with a molecular weight of 200 to 1000 is separated together with sulfate into nanofiltration concentrated water for recycling, and a nanofiltration clear liquid with glycerol as the main component is obtained, and the nanofiltration clear liquid is used as a glycerol solution.

[0064] Glycerol solution can be used as a carbon source for denitrification in sewage treatment plants. It has good biodegradability, is safe and reliable, and can be further used to produce various water treatment carbon sources by adding additives.

[0065] In the step 1, when water is added to dilute the glycerol residue whose inorganic salt component is mainly chloride, the specific gravity is controlled to be between 1 and 1.05 and the salinity is controlled to be between 5000 and 50000 mg / L.

[0066] In the step 2, a filter press is used to filter the glycerol dilution in the step 1 to remove colloidal impurities.

[0067] After the glycerin residue dilution is added to the reactor 5 in step 3, the agitator of the reactor 5 is started, the agitator speed is 80-500 r / min, and the temperature of the glycerin residue dilution in the reactor 5 is controlled at 10-30° C., and then calcium oxide and sodium aluminate are added to react. The glycerin residue dilution, calcium oxide and sodium aluminate react in the reactor 5 while being stirred, and the reaction is sufficient.

[0068] The Fred salt precipitate obtained in step 3 is separated by filter pressing and then recycled as a raw material for heavy metal capture agent. Fred salt can effectively remove harmful anions (such as arsenate, chromate, selenate, antimonate, etc.) and inorganic heavy metal cations (cadmium ions, copper ions, lead ions, nickel ions, etc.) in wastewater. By adding certain auxiliary agents, a heavy metal capture agent can be prepared for heavy metal removal in electroplating wastewater.

[0069] The calcium carbonate precipitate separated in step 4 is purified by washing to obtain refined calcium carbonate for industrial production.

[0070] The inorganic salts in the nanofiltration concentrated water obtained in step 7 are adsorbed by ion resin to obtain refined polyglycerol for industrial production. The low-polymerization degree polyglycerol with a molecular weight of 200 to 1000 obtained in step 7 is mainly 2- to 9-polymerization degree polyglycerol. These low-polymerization degree polyglycerols are used in cosmetics, fiber industry, and plastic industry. The inorganic salts in the nanofiltration concentrated water are adsorbed by ion resin to obtain refined polyglycerol for industrial production.

[0071] A glycerin residue recycling treatment system comprises a glycerin residue dilution tank 1, a primary filter press 2, a secondary filter press 3, a tertiary filter press 4, a reactor 5, a filtrate conditioning tank 6, a chloride ion concentration detector, a microfiltration membrane device 8, a microfiltration water production bucket 9, an ultrafiltration membrane device 10, an ultrafiltration water production bucket 11 and a nanofiltration membrane device 12. The glycerin residue dilution tank 1 is connected with the inlet of the primary filter press 2 through a pipeline. The glycerin residue dilution liquid in the glycerin residue dilution tank 1 can be sent into the filter press through a lifting pump. The filter press can filter the glycerin dilution liquid to remove colloidal impurities. The water filtration port of the filter press is connected with the liquid inlet of the reactor 5 through a pipeline, and the filtrate is then transported into the reactor 5. The reactor 5 The reactor 5 is also provided with a reagent adding port, a supernatant discharge port and a precipitation discharge port which can be opened and closed. The reagent adding port is used for adding reagents, the supernatant discharge port is used for discharging the supernatant formed by precipitation after the reaction in the reactor 5, and the precipitation discharge port is used for discharging the precipitation at the bottom of the reactor 5. The precipitation discharge port of the reactor 5 is connected with the inlet of the secondary filter press 3 through a pipeline. The secondary filter press 3 can filter and dehydrate the water-containing precipitation discharged from the reactor 5 to obtain solid Fred salt. The supernatant discharge port of the reactor 5 is connected with the water inlet of the filtrate conditioning tank 6 through a pipeline. The chloride ion concentration detector can detect the chloride ion concentration of the liquid in the filtrate conditioning tank 6. The liquid conditioning tank 6 is also connected to the liquid inlet of the reactor 5 through a pipeline. The liquid in the filtrate conditioning tank 6 that has been detected to have excessive chloride ion concentration can be sent back to the reactor 5 through a lifting pump. The filtrate conditioning tank 6 is provided with a dosing port, a conditioning clear liquid discharge port and a precipitation separation port. The dosing port is used to add a reagent. The precipitation separation port of the filtrate conditioning tank 6 is connected to the inlet of the three-stage filter press 4 through a pipeline. The three-stage filter press 4 can filter and dehydrate the water-containing precipitate discharged from the filtrate conditioning tank 6 to obtain solid calcium carbonate. The conditioning clear liquid discharge port of the filtrate conditioning tank 6 is connected to the liquid inlet of the microfiltration membrane device 8 through a pipeline. The microfiltration membrane in the microfiltration membrane device 8 can condition the precipitate discharged from the filtrate conditioning tank 6. Microfiltration treatment is carried out at night, and the microfiltration clear liquid of the microfiltration membrane device 8 is discharged into the microfiltration water production bucket 9 through a pipeline, and the microfiltration water production bucket 9 is connected with the liquid inlet of the ultrafiltration membrane device 10 through a pipeline. The microfiltration clear liquid in the microfiltration water production bucket 9 can be sent into the ultrafiltration membrane device 10 through a lifting pump, and the ultrafiltration membrane of the ultrafiltration membrane device 10 can perform ultrafiltration treatment on the microfiltration clear liquid. The ultrafiltration clear liquid of the ultrafiltration membrane device 10 is discharged into the ultrafiltration water production bucket 11 through a pipeline, and the ultrafiltration water production bucket 11 is connected with the liquid inlet of the nanofiltration membrane device 12 through a pipeline. The ultrafiltration clear liquid in the ultrafiltration water production bucket 11 can be sent into the nanofiltration membrane device 12 through a lifting pump, and the nanofiltration membrane of the nanofiltration membrane device 12 can perform nanofiltration treatment on the ultrafiltration clear liquid. After the glycerol residue is diluted, various substances in the glycerol residue dilution liquid are gradually separated and valuable substances are recycled, which effectively improves the resource treatment effect of the glycerol residue.

[0072] There are also Fred salt deep processing equipment 13, calcium carbonate washing and purification equipment 14, high polymerization degree polymerized glycerol deep processing equipment 15, low polymerization degree polymerized glycerol deep processing equipment 16 and glycerol solution deep processing equipment 17. The Fred salt deep processing equipment 13 is provided with a feed inlet for adding solid Fred salt and an auxiliary agent addition inlet for adding auxiliary agents. The Fred salt deep processing equipment 13 can prepare the solid Fred salt produced by the secondary filter press 3 with auxiliary agents to prepare a solid heavy metal capture agent. The calcium carbonate washing and purification equipment 14 can wash and remove impurities from the calcium carbonate-containing solid material produced by the tertiary filter press 4 to obtain a high-purity solid refined calcium carbonate product. The ultrafiltration concentrate discharge port of the ultrafiltration membrane device 10 is connected to the feed inlet of the high polymerization degree polymerized glycerol deep processing equipment 15 through a pipeline, and the ultrafiltration concentrate can be discharged into In the high-polymerization-degree polymerized glycerol deep processing equipment 15, the high-polymerization-degree polymerized glycerol deep processing equipment 15 can prepare the high-polymerization-degree polymerized glycerol in the ultrafiltration concentrate through additives to prepare liquid cement grinding aids. The nanofiltration concentrate discharge port and the nanofiltration clear night discharge port of the nanofiltration membrane device 12 are respectively connected to the liquid inlets of the low-polymerization-degree polymerized glycerol deep processing equipment 16 and the glycerol solution deep processing equipment 17 through pipelines. The nanofiltration concentrate and the nanofiltration clear night can be discharged into the low-polymerization-degree polymerized glycerol deep processing equipment 16 and the glycerol solution deep processing equipment 17 respectively. The low-polymerization-degree polymerized glycerol deep processing equipment 16 is provided with an ion resin, which can nanofilter the inorganic salts in the concentrate to finally obtain liquid refined polymerized glycerol. The glycerol solution deep processing equipment 17 can prepare the nanofiltration clear night through additives to prepare a liquid water treatment carbon source. Fred salt, calcium carbonate, high-polymerization degree polyglycerol, low-polymerization degree polyglycerol and glycerol solution separated from the glycerol residue dilution liquid are processed separately in depth, and finally the products that can be directly sold and used are produced, thus realizing greater economic value.

[0073] The glycerin residue dilution tank 1, the reactor 5 and the filtrate conditioning tank 6 are all provided with a stirrer 7 for stirring the mixture. The stirrer 7 is used to stir the mixture so that the mixture is mixed more evenly.

Claims

1. A glycerin residue recycling process, characterized in that: The steps include: Step 1: Glycerine residue dilution: Dilute the glycerin residue whose inorganic salt components are mainly chloride salts with water; Step 2: Filter and remove impurities: Filtering the glycerin residue dilution to remove colloidal impurities in the glycerin residue dilution; Step 3: Freund's salt method for dechlorination: The filtered glycerine residue dilution liquid is pumped into a reactor, and calcium oxide and sodium aluminate are added to the reactor to react to generate Fred salt, and the Fred salt precipitate produced by the reaction is separated from the supernatant, the Fred salt precipitate is recycled, and the supernatant flows out, wherein the addition amount of calcium oxide and sodium aluminate is according to n(Ca):n(Al):n(Cl)=5-20:2-5:1; Step 4: Filtrate conditioning: Testing the chloride ion content of the supernatant after separating the Fred salt precipitate in step 3; If the chloride ion content is >500 mg / L, repeat step 3; If the chloride ion content is ≤500 mg / L, sulfuric acid is added to adjust the pH of the supernatant to neutral, and sodium carbonate is added to react with calcium ions in the supernatant after separation of Fred salt precipitation to form calcium carbonate. The amount of sodium carbonate added is based on the standard that no precipitation is generated by continuing to add sodium carbonate to the supernatant after separation of Fred salt precipitation, and the calcium carbonate precipitate is separated and recycled; Step 5: Microfiltration to remove glue: The supernatant produced in step 4 is filtered using a microfiltration membrane to separate the macromolecular organic matter with a molecular weight greater than 1 million and the residual colloid into a microfiltration concentrate to obtain a microfiltration clear liquid; Step 6: Ultrafiltration separation: The microfiltration clear solution is filtered through an ultrafiltration membrane, and the high-polymerization degree polyglycerol with a molecular weight of more than 1000 is separated into an ultrafiltration concentrate for recovery as a raw material for liquid cement grinding aid, and ultrafiltration clear solution is obtained at the same time; Step 7: Nanofiltration separation: The ultrafiltration clear is filtered through a nanofiltration membrane, and low-polymerization degree polyglycerol with a molecular weight of 200 to 1000 is separated together with sulfate into nanofiltration concentrated water for recycling, and a nanofiltration clear liquid with glycerol as the main component is obtained, and the nanofiltration clear liquid is used as a glycerol solution.

2. The glycerin residue recycling process according to claim 1, characterized in that: In the step 1, when water is added to dilute the glycerol residue whose inorganic salt component is mainly chloride, the specific gravity is controlled to be between 1 and 1.05 and the salinity is controlled to be between 5000 and 50000 mg / L.

3. The glycerin residue recycling process according to claim 1, characterized in that: In the step 2, a filter press is used to filter the glycerol dilution in the step 1 to remove colloidal impurities.

4. The glycerin residue recycling process according to claim 1, characterized in that: After the glycerin residue dilution is added into the reactor in step 3, the agitator of the reactor is started, the agitator speed is 80-500 r / min, and the temperature of the glycerin residue dilution in the reactor is controlled at 10-30° C., and then calcium oxide and sodium aluminate are added to react.

5. The glycerin residue recycling process according to claim 1, characterized in that: The Fred salt precipitate obtained in step 3 is separated by filtration and then recycled as a raw material for heavy metal capture agent.

6. The glycerin residue recycling process according to claim 1, characterized in that: The calcium carbonate precipitate separated in step 4 is purified by washing to obtain refined calcium carbonate for industrial production.

7. The glycerin residue recycling process according to claim 1, characterized in that: The inorganic salt in the nanofiltration concentrated water obtained in step seven is adsorbed by ion resin to obtain refined polyglycerol for industrial production.

8. A glycerin residue recycling treatment system used in the glycerin residue recycling process according to claims 1 to 7, characterized in that: The invention comprises a glycerin residue dilution tank (1), a primary filter press (2), a secondary filter press (3), a tertiary filter press (4), a reactor (5), a filtrate conditioning tank (6), a chloride ion concentration detector, a microfiltration membrane device (8), a microfiltration water production tank (9), an ultrafiltration membrane device (10), an ultrafiltration water production tank (11) and a nanofiltration membrane device (12). The glycerin residue dilution tank is connected to the inlet of the primary filter press through a pipeline. The glycerin residue dilution liquid in the glycerin residue dilution tank can be fed into the filter press through a lifting pump. The filter press can filter the glycerin dilution liquid to remove colloidal impurities. The water filter port of the filter press is connected to the liquid inlet of the reactor through a pipeline. The filtrate is then transported to the reactor. The reactor is also provided with a reagent addition port, a supernatant discharge port and a precipitation discharge port which can be opened and closed. The reagent addition port is used for adding reagents, the supernatant discharge port is used for discharging the supernatant formed by precipitation after the reaction in the reactor, and the precipitation discharge port is used for discharging the precipitation at the bottom of the reactor. The precipitation discharge port of the reactor is connected with the inlet of the secondary filter press through a pipeline. The secondary filter press can filter and dehydrate the water-containing precipitation discharged from the reactor to obtain solid Fred salt. The supernatant discharge port of the reactor is connected with the water inlet of the filtrate conditioning tank through a pipeline. The chloride ion concentration detector can detect the chloride ion concentration in the filtrate conditioning tank. The liquid is tested for chloride ion concentration. The filtrate conditioning tank is also connected to the liquid inlet of the reactor through a pipeline. The liquid in the filtrate conditioning tank that has detected excessive chloride ion concentration can be sent back to the reactor through a lifting pump. The filtrate conditioning tank is provided with a dosing port, a conditioning clear liquid discharge port and a precipitation separation port. The dosing port is used to add a medicament. The precipitation separation port of the filtrate conditioning tank is connected to the inlet of a three-stage filter press through a pipeline. The three-stage filter press can filter and dehydrate the water-containing precipitate discharged from the filtrate conditioning tank to obtain solid calcium carbonate. The conditioning clear liquid discharge port of the filtrate conditioning tank is connected to the liquid inlet of a microfiltration membrane device through a pipeline. The microfiltration in the microfiltration membrane device The membrane can perform microfiltration treatment on the conditioned clear liquid discharged from the filtrate conditioning tank. The microfiltration clear liquid of the microfiltration membrane device is discharged into the microfiltration water production barrel through a pipeline. The microfiltration water production barrel is connected with the liquid inlet of the ultrafiltration membrane device through a pipeline. The microfiltration clear liquid in the microfiltration water production barrel can be sent into the ultrafiltration membrane device through a lifting pump. The ultrafiltration membrane of the ultrafiltration membrane device can perform ultrafiltration treatment on the microfiltration clear liquid. The ultrafiltration clear liquid of the ultrafiltration membrane device is discharged into the ultrafiltration water production barrel through a pipeline. The ultrafiltration water production barrel is connected with the liquid inlet of the nanofiltration membrane device through a pipeline. The ultrafiltration clear liquid in the ultrafiltration water production barrel can be sent into the nanofiltration membrane device through a lifting pump. The nanofiltration membrane of the nanofiltration membrane device can perform nanofiltration treatment on the ultrafiltration clear liquid.

9. The glycerin residue recycling system according to claim 8, characterized in that: There are also Fred salt deep processing equipment (13), calcium carbonate washing and purification equipment (14), high polymerization degree polymerized glycerol deep processing equipment (15), low polymerization degree polymerized glycerol deep processing equipment (16) and glycerol solution deep processing equipment (17). The Fred salt deep processing equipment is provided with a feed port for adding solid Fred salt and an auxiliary agent addition port for adding auxiliary agents. The Fred salt deep processing equipment can prepare solid heavy metal capture agents by mixing the solid Fred salt produced by the secondary filter press with auxiliary agents. The calcium carbonate washing and purification equipment can wash and remove impurities from the solid calcium carbonate-containing material produced by the tertiary filter press to obtain a high-purity solid refined calcium carbonate product. The ultrafiltration concentrate discharge port of the ultrafiltration membrane device is connected to the feed port of the high polymerization degree polymerized glycerol deep processing equipment through a pipeline. The ultrafiltration concentrate can be discharged into the high-polymerization-degree polyglycerol deep processing equipment, and the high-polymerization-degree polyglycerol deep processing equipment can prepare the high-polymerization-degree polyglycerol in the ultrafiltration concentrate through additives to produce liquid cement grinding aids. The nanofiltration concentrate discharge port and the nanofiltration clear night discharge port of the nanofiltration membrane device are respectively connected to the liquid inlets of the low-polymerization-degree polyglycerol deep processing equipment and the glycerol solution deep processing equipment through pipelines. The nanofiltration concentrate and the nanofiltration clear night can be discharged into the low-polymerization-degree polyglycerol deep processing equipment and the glycerol solution deep processing equipment respectively. The low-polymerization-degree polyglycerol deep processing equipment is provided with an ion resin, which can nanofilter the inorganic salts in the concentrate to finally obtain liquid refined polyglycerol. The glycerol solution deep processing equipment can prepare the nanofiltration clear night through additives to produce a liquid water treatment carbon source.

10. The glycerin residue recycling system according to claim 8, characterized in that: The glycerin residue dilution tank, the reaction kettle and the filtrate conditioning tank are all provided with a stirrer (7) for stirring the mixture.

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